9528(  1) - 12/06/01 12:39  - [  1]

    PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS   ST ScI Use Only
                                                       ID:      9528
                                                       Version: 1
                                                       Check-in Date: 06-Dec-2001
                                                                      11:45:48

1.Proposal Title:
Compact Groups in the HST Archive: Playing the morphology card
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2. Proposal For  3. Cycle
AR               11
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4. Investigators
                                                                                     Contact?
    PI: Stephen Odewahn                   Arizona State University
   CoI: Dr. Paul Hickson                  University of British Columbia                N
   CoI: Mr. Seth Cohen                    Arizona State University                      N

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5. Abstract

Compact groups of galaxies have been the subject of intense observational and
theoretical scrutiny, because they may well play a fundamental role in galaxy
evolution. These objects are the sites of rapid merger events. We propose an
archival search for moderate redshift compact groups to achieve these goals:
beginenumerate em Use archival WFPC2, STIS, and ACS images to collect candidate
compact groups at redshifts in the range 0.5 z 1. em Apply new Fourier-based image
analysis methods to identify tidally disturbed group members, thereby increasing the
likelihood of identifying true physical associations. em Carry out a program of
spectroscopic followup (using the upgraded MMT) to confirm the group nature of these
galaxy aggregates. endenumerate There is strong evidence for an epoch-dependent
merger rate, and we will use our confirmed compact groups as probes for detecting
this. If the merger rate does indeed increase substantially at z\cge0.5, then we
expect to see a strong increase in the number of observed compact groups, the most
extreme manifestations of merging.
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                                                9528(  1) - 12/06/01 12:39  - [  2]

            Summary Form for Proposal  9528

  Item                         Used in this proposal
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  Proposal Category            AR
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